## Facts

- Bougainville residents sued Rio Tinto entities over conduct tied to the Panguna copper mine and events during the Bougainville conflict in Papua New Guinea (PNG).
- Plaintiffs alleged severe environmental damage and health harms from mine operations.
- Plaintiffs alleged racial discrimination in employment and facilities, including wage disparities and segregation.
- Plaintiffs alleged Rio Tinto’s conduct contributed to violent suppression of protests and assisted PNG’s blockade of Bougainville, including restrictions affecting food and medical supplies.
- Plaintiffs sought to hold Rio Tinto liable for its own acts and for alleged collaboration with, or agency/partnership by, the PNG government.
- Plaintiffs brought claims under the Alien Tort Statute (ATS), alleging genocide, war crimes, crimes against humanity, and racial discrimination as violations of the law of nations, plus additional non-federal tort claims.
- The district court issued a mixed order dismissing or staying claims on political question, act of state, international comity, and prudential exhaustion grounds; both sides took interlocutory appeals.

## Issues

1. Whether the political question doctrine barred adjudication of claims implicating foreign relations and a foreign sovereign’s conduct.
2. Whether the act of state doctrine required dismissal because adjudication would pass on the validity of PNG’s sovereign acts within its territory.
3. Whether international comity required dismissal or abstention in favor of PNG’s interests or fora.
4. Whether ATS claims are subject to a prudential exhaustion requirement of local remedies, and if so, how it applies.
5. Whether the pleaded ATS claims alleged violations of specific, universal, and obligatory international law norms cognizable under the ATS.

## Decision

- The Ninth Circuit largely reversed or vacated the district court’s threshold dismissals and remanded for further proceedings.
- The court held that political question concerns did not categorically bar the case; most claims could proceed at the pleading stage.
- The court declined to apply the act of state doctrine as a broad bar, emphasizing the need to assess whether adjudication required validating sovereign acts and noting reduced force where jus cogens violations were alleged.
- The court treated international comity as a prudential, case-specific consideration and concluded it did not warrant dismissal of most claims on the existing record.
- The court did not impose a rigid exhaustion prerequisite under the ATS; it treated exhaustion as a flexible prudential consideration potentially relevant on remand.
- The court recognized that allegations of genocide, war crimes, and crimes against humanity fall within universally accepted international norms for ATS purposes, while signaling greater caution for environmental claims as customary international law.

## Legal Principles

- ATS jurisdiction extends only to claims based on a narrow class of international law norms that are specific, universal, and obligatory.
- Foreign policy sensitivity does not, by itself, render ATS litigation nonjusticiable under the political question doctrine; Baker v. Carr factors govern.
- The act of state doctrine is not jurisdictional and applies only where adjudication requires a U.S. court to declare invalid a foreign sovereign’s official public acts; its application is weaker where plaintiffs allege violations of peremptory international norms.
- International comity operates as a discretionary, prudential doctrine requiring case-specific weighing of competing sovereign interests, not a categorical dismissal rule.
- The ATS contains no textual exhaustion requirement; any exhaustion obligation is prudential and context dependent, and may be less appropriate for claims alleging universally condemned international crimes.

## Conclusion

The Ninth Circuit permitted most ATS claims arising from alleged international law violations connected to Rio Tinto’s Bougainville operations to proceed past threshold justiciability doctrines, rejected sweeping political question, act of state, and comity dismissals, and treated local-remedies exhaustion as a discretionary prudential inquiry to be evaluated on remand.


Sarei v. Rio Tinto, PLC, 456 F.3d 1069 (9th Cir. 2006)